42. Which of the following elements is essential to be structural components of cells and tissues in animal life?
(A) Silicon (Si)
(B) Helium (He)
(C) Carbon ( C )
(D) Hydrargyrum (Hg)

38. Which description of gluconeogenesis is   NOT   correct? (A) Glucose molecules are synthesized from non-carbohydrate precursors. (B) The reaction of gluconeogenesis is totally the reverse of glycolysis. (C) Fructose-1,6-bispohosphate is converted to fructose-6-phosphate by fructose bisphosphate phosphatase. (D) Glucose-6-phosphate is converted to glucose by Glucose-6-phosphatase.

39. Which description of acetyl-CoA is correct? (A) Pyruvate is converted to acetyl-CoA, which then enters the citric acid cycle. (B) Acetyl-CoA cannot be transported directly across the mitochondrial membrane. (C) During the citric acid cycle, acetyl-CoA transfers its acetyl group to oxaloacetate to form citrate. (D) All of above

40. Glutamine is degraded to form , CO2 and H2O. How many molecules of ATP can be generated from 1 mole of glutamine? (assuming that each NADH yields 2.5 ATP and each FADH2 yields 1.5 ATP)? (A) 23.5 (B) 25.5 (C) 27.5 (D) 30

41. Which description is   NOT   correct about cellular foundations? (A) All cells are bounded by a plasma membrane. (B) All organisms require a source of energy to perform cellular work. (C) Bacterial and archaeal cells contain a nucleus. (D) Eukaryotic cells are multi-compartmented, with certain processes segregated in specific organelles.

43. The human red blood cells burst when they are placed in the water. Which of the following will cause Escherichia coli ((E) coli) to burst completely in it? (A) Isotonic solution (B) Hypertonic solution (C) Hypotonic solution (D) None of above

44. The phosphate buffer system is maximally effective at a pH close to its pKa of 6.86 and thus tends to resist pH changes in the range between about 5.9 and 7.9. What is the pH of a mixture of 0.05 M NaH2PO4 and 0.5 M Na2HPO4? (A) 5.86 (B) 6.86 (C) 7 (D) 7.86

45. How many cycles of β-oxidation are required to completely process a saturated stearic acid (C18)? (A) 7 (B) 8 (C) 9 (D) 18

46. The β-oxidation of saturated fatty acids has four basic steps. The important enzymes involved in the reaction are listed below: 1. enoyl-CoA hydratase 2. acyl-CoA dehydrogenase 3. β-hydroxyacyl-CoA dehydrogenase 4. acyl-CoA acetyltransferase Which of the following is the correct order that they react in the β-oxidation pathway? (A) 1234 (B) 4321 (C) 2134 (D) 3421

47. Which of the following is   NOT   a ketone body? (A) Acetyl-CoA (B) Acetone (C) β-hydroxybutyrate (D) Acetoacetate

48. Which description is   NOT   correct about the catabolism of amino acids? (A) An early step in the catabolism of amino acids is the separation of the amino group from the carbon skeleton. (B) The amino group is transferred to α-ketoglutarate to form glutamate. (C) The amino group transamination reaction requires the coenzyme pyridoxal phosphate. (D) Glutamate dehydrogenase liberates the amino group as ammonium ion (NH4+) in the liver peroxisome.